Harper Lee, whose first novel, “To Kill a Mockingbird,” about racial injustice in a small Alabama town, sold more than 10 million copies and became one of the most beloved and most taught works of fiction ever written by an American, has died. She was 89.

Her death was confirmed by Mary Jackson, the city clerk in Monroeville, Ala., where Ms. Lee lived. Ms. Jackson could not say where or when Ms. Lee died.

The instant success of “To Kill a Mockingbird,” which was published in 1960 and won the Pulitzer Prize for fiction the next year, turned Ms. Lee into a literary celebrity, a role she found oppressive and never learned to accept. The enormous success of the film version of the novel, released in 1962 with Gregory Peck in the starring role of Atticus Finch, a small-town Southern lawyer who defends a black man falsely accused of raping a white woman, only added to Ms. Lee’s fame and fanned expectations for her next novel.